Stay-bolt.



E. W. CLARK.

STAY BOLT.

APPLIOATION FILED oo'r.1s.191o.

Patented Sept. 19,1911.

EDWARD W. CLARK, 035 LOS ANGELES, CALIFORNIA.

STAY-BOLT.

Specification of Letters Patent. Patented Sept. 19, 1911.

Application filed October 13, 1910. Serial No. 586,822.

T 0 all whom it may concern."

Be it known that I, EDWARD l/V. CLARK, a citizen of the United States,residing in the city of Los Angeles, county of Los Angeles, State ofCalifornia, have invented new and useful Improvements in Stay-Bolts, ofwhich the following is a specification.

My invention relates to a flexible staybolt for securing the fire box ofa boiler to the head or shell thereof; and the object thereof is toprovide a. flexible stay-bolt which can be quickly and accuratelysecured in place, and which will make steam tight joints and at the sametime allow a slight vibration between the parts without undue strain onany of the parts; a further object is to produce a flexible stay-boltwhich may be positioned for use when the holes in the fire box and shellof the boiler are not in perfect alinement. I accomplish these objectsby the stay-bolt described herein and illustrated in the accompanyingdrawings forming a part hereof in which:

Figure 1 is a side elevation of my staybolt, partly in section, in placein a fragment of the fire box wall and a fragment of the boiler head.Fig. 2 is an end view of the shaft of my improved bolt detached from thethimbles. Fig. 3 is an end elevation of a thimble before being swagedupon the head of the shaft, viewed from the end showing the lug whichprevents the rotation of the thimble on the shaft after the thimble isswaged thereon. Fig. 4 is a modified form of stay-bolt.

In the drawings 5 is the outer shell or boiler head, which is providedwith the necessary perforations 6 for the reception of the outerthimbles 7 which are swaged therein in the usual well known manner.These outer thimbles preferably consist of a tube which is provided witha partition 8, which divides the tube into two parts. Upon one side ofthe partition is an angular shaped lug 9 which is preferably in shape,the frustum of a pyramid.

A connecting shaft 10 has semi-globular heads 11 provided with angularshaped sockets 12 into which the partition lug is received to preventthe rotation of one part in the other. In the drawings these sockets aresquare. Both ends or heads of the shaft are finished alike. The innerthimble consists of a tube 14, which has a closed and reduced inner end15 which is circular and externally screw threaded, and when positionedfor use, screws into apertures 16 in the fire box wall 17 The innerthimbles are provided with lugs 18 of the same form as the lugs of theouter thimble, which enter like recesses in the ends of the shaft. Theinner and outer thimbles are swaged upon the heads of the shaft as shownin Fig. 1, so as to leave a small space between the partitions of thethimbles and the heads of the shaft as shown at 19 and 20 in Fig. 1.After the thimbles have been swaged upon the heads of the shaft, thecompleted staybolt is partly passed into an aperture in the outer shellor head and screwed into an aperture in the fire box, appropriate toolsbeing used for that purpose. After the inner thimble is screwed to placethe outer thimble is swaged at its outer end to secure it in the head orshell of the boiler in the usual well known manner.

By this construction it will be seen that the fire box may haveconsiderable vibration without straining the connection between thethimbles and the shells, as the semiglobular head allows the thimbles torotate slightly thereon.

It will also be observed that should the holes in the boiler head orshell and in the fire box be slightly out of alinement the inner thimblecan be screwed into place, notwithstanding such want of alinement.

It will also be observed that-this form of stay-bolt may be used wherethe boiler head and fire box shell are not parallel with each other, andstill permit the holes for the thimbles to be bored through therespective parts at right angles to the faces or planes of the same.

If desired the inner thimbles can be of the same form as the outer oneand can be secured by swaging in the same manner. Any angular shaped lugand depression which will keep the shaft from turning in the thimble maybe used instead of the forms shown and any other form of head for theshaft which will permit of oscillation when in use, may be used but Iprefer the semiglobular form as it is the best.

It will be observed that the partition in the outer thimble makes thejoint between it and the shaft absolutely tight without the use ofcalking or washers.

In Fi l I have shown a modification of my pre erred form of bolt. Inthis form the shaft 10 has only one enlar ed end 11 which is preferablysemi-cylm meal and only one thimble 6, which is the outer thimble, isused. The inner end 22 of the shaft is tapered and threaded and screwsinto a taper threaded hole 23 in the fire boX wall 17, thereby making asteam tight joint. The outer end of the shaft and the outer thimble arein all respects the same as in my preferred construction. In the use ofthis bolt it will be observed that there is only half as much vibrationprovided for be tween the parts as in my preferred form; but'where thedistance between the fire box wall and the outer shell is short or wherecheapness of construct-ion is desirable this modification may be used.

Having described my invention what I claim is 1. A flexible stay-boltcomprising a central shaft having semi-globular heads at the endsthereof, said heads having angular recesses therein; an outer thimblehaving a partition therein swaged upon one of the heads of said shaft,said partition having an angularly formed lug projecting into the recessin the head; an inner thimble swaged upon the other head of said shaft,said thimble having an angular lug projecting into the depression in thehead of the shaft, and having a reduced threaded inner end.

2. A flexible stay-bolt comprising a central shaft having enlarged ends;and thimbles mounted upon said enlarged ends by swaging, and adapted tooscillate, but not rotate thereon, said thimbles being adapt-ed to besecured in the respective parts ,united by the bolt.

3. A stay bolt composed of two sections connected together to preventindependent rotary movement, one of said sections consisting of a bolthaving a head at one end and being screw threaded at the other end, andthe other section consisting of a tubular member having a partitionintermediate its ends, one of the ends of said tubular member beingswaged around the head of the other member.

In witness that I claim the foregoing I have hereunto subscribed my namethis 4th day of October, 1910.

G. E. HARPHAM, C. M. AUSTIN.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents, Washington, D. C.

